A problem posed with this type of pulse is to find the time at which its maximum value occurs. In effect it is important to determine in a most precise manner the time of this maximum value if one wishes to obtain good performance, for example, with an M.L.S. radio navigation system.
Despite the fact that the invention relates more particularly to this system, it will be obvious that the invention also relates to the applications for which one is confronted with this type of problem.
The solution to this problem essentially meets with two kinds of difficulties. The first difficulty is due to the fact that the transmitted pulses are subject to different reflections and are received distorted. The second difficulty is that they can be affected by the noise. Consequently, the detected maximum value is not exactly that of the transmitted pulse.
In European Patent Specification No. 0 192 876, such a method is described which provides measures to solve this problem. However, these measures remain insufficient for providing an exact time especially when the received pulses are embedded in noise.